Engineers use downhole spectrometers to monitor, analyze, or identify different properties of fluid, such as contamination, composition, fluid type, and PVT (“pressure, volume, temperature”) properties. For example, a spectrometer may be coupled to a formation fluid sampling tool to analyze fluids in real time as they are drawn from the formation. During the sampling operation the spectrometer can monitor contamination levels from borehole fluids and, once the contamination has fallen to an acceptable level, the spectrometer can measure spectral characteristics of the formation fluid to identify its components. Fluid component identification is helpful for determining whether and how production should be performed from a particular area of the well. It can provide indications of reservoir continuity, blowout risk, production value, etc.
Despite the evident utility of downhole spectrometers, the range of measurements that can be made by existing tools is somewhat limited. In the case of filter wheel spectrometers, this limitation is primarily due to spatial constraints on the filter wheel itself.